1. Field of the Invention
The invention relates in general to a filtering system, a filtering method, a TV signal receiver and a TV signal receiving method, and more particularly, to a filtering system, a filtering method, a TV signal receiver and a TV signal receiving method that filter signals in collaboration with frequency translation.
2. Description of the Related Art
A TV system down-converts one or multiple channels to obtain TV data. However, if an overall bandwidth of the system is too large or there are a large number of channels, it is possible that channels having harmonic frequencies be also down-converted. For example, when down-converting a 100 MHz channel, channels in corresponding odd harmonic frequencies (e.g., 300 MHz or 500 MHz) may also be down-converted. Signals of these channels may become superimposed to affect the accuracy of desired data of the channels.
As the frequency range covered by TV signals is vast, e.g., from 40 MHz to 1000 MHz, a considerable number of channels are covered. Individual signal strengths of these channels are different, and so a front-end circuit is required to have a remarkably large dynamic range in order to handle all of the channels. As a result, linearity of the front-end circuit may be attenuated. Further, to obtain TV data of multiple channels, multiple tuners may be connected in series into a loop in certain TV systems. Under such architecture, signal loss may rise due to the loop, in a way that power consumption as well as costs are increased.